ES2748107T3 - Procedure and device for the treatment of telephone calls directed to inaccessible mobile phones - Google Patents

Abstract

A method for processing telephone calls in a mobile network comprising mobile switching nodes (2) and for processing data relating to said telephone calls, in which, for a telephone call from a calling subscriber (1'; 1") to a mobile telephone of a called subscriber, the procedure comprises the steps of: I- establishing a connection with a device (9) for storage and management of data related to the telephone call, when the called subscriber is not accessible, due to the mobile phone being in the disconnected mode or due to the absence of a radio frequency signal, and when, at the same time, a call forwarding service to an answering service or another telephone number is not operational; cooperating said storage and management device (9) with the mobile switching nodes (2) by managing a signaling protocol; II- in said storage and management device (9), re receive only the signaling component of the telephone call and extract the telephone number of the calling party from the received signaling component of the telephone call, and record the telephone number and time/date of the telephone call in a list of numbers comprising the telephone numbers of the calling subscribers who have already attempted to access the called subscriber's mobile telephone; IIIa- in said storage and management device (9), cooperate through a protocol with its own Position Register (3) to receive from said own Position Register (3) a notification when the called subscriber's mobile telephone is accessible again; and IIIb- at the moment in which the called subscriber's mobile phone is accessible again, sending from said storage and management device (9) to a short message service center (11) messages that include data, related to telephone calls , which are included in said list of numbers; IV- send from the short message service center (11), to the called subscriber's mobile phone, SMS messages that include said data.

Description

DESCRIPTION

Procedure and device for the treatment of telephone calls directed to inaccessible mobile phones Field of the invention

[0001] The present invention relates generally to the problem of establishing communication with a subscriber in a cellular cellular mobile network via radio, and more particularly relates to a telecommunication service via a cellular cellular mobile network via radio, which allows a subscriber acquire the telephone number of the subscriber who tried to call it while it was not accessible due to the absence of radio signaling, or because the mobile phone was in disconnected mode. The invention is related both to the procedure for implementing this service and to the functions of special devices used when it is provided.

Background of the Art

[0002] Recent estimates suggest that for every telephone network operator, which is currently linked to the public mobile radio service in Italy, there are tens of millions of telephone calls daily that are unsuccessful because the "target" mobile telephone is not accessible or is in offline mode.

[0003] In other words, despite the increasing use of telephone answering systems (answering services) and call forwarding services, it is nevertheless the case that, in some special conditions, more than 400 calls / second are lost, thus limiting the extent of outgoing traffic or, in any case, providing a restricted or partially complete service to subscribers.

[0004] The basic difficulty encountered by a network administrator in addressing this type of problem is that of traversing considerable traffic.

[0005] In fact, the problem of registration and management - at the same time - of such a remarkable amount of data due to the large number of failed calls, the difficulties caused by a consistent evaluation of the geographical burden of this service, the management Possible network failures, etc., have led to the situation that - until now - a solution to this problem has not been considered or implemented. This problem does not lend itself to a simple solution, since many reasons may be the cause of the impossibility of establishing a communication: - the mobile phone via radio may be in disconnected mode, the network having acquired the signal confirming this fact ( disconnected),

- the battery is discharged or disconnected from its operating position, or the SIM card is not inserted;

- there may be a condition in which the transceiver station is not accessible or is not visible, since the radio channel is notoriously very random; etc.

[0006] Finally, it would be necessary - in any case - to verify the possible enabling of the call forwarding service to the answering system or to an additional telephone number.

[0007] Furthermore, these conditions, according to which it is impossible to access a called subscriber, have up to now been accepted by the users of the mobile service via radio as intrinsically predictable but totally unavoidable. In other words, this problem regarding the impossibility of establishing a connection has never arisen, because, compared to the fixed network, it was evident that the cellular telephone network would necessarily lead to this drawback, due to the intrinsic nature of the operating principle. from a mobile phone, which may be temporarily unavailable or in disconnected mode.

[0008] Document EP0699009 describes a procedure in which telephone calls lost due to the inaccessibility of a called subscriber B are handled in part by a first mobile gateway gateway (GMSC) of the mobile network, which receives the call by phone, and in part by a Short Message Service Center (SMSC) connected to the GMSC. The GMSC checks whether the called subscriber B is accessible or not, and - if the called subscriber B is not accessible - the GMSC forwards the subscriber identification code A-ID of the calling subscriber A to the SMSC. The SMSC contains a COMP communications computer, which, with the help of the subscriber identification code A-ID, generates a message in the form of a short message SM and stores it in a MEM memory component connected to the COMP communications computer. When called subscriber B is reachable, the GMSC signals the new state to the SMSC so that the communication computer COMP can send the stored short message to called subscriber B.

[0009] An object of the present invention is to provide treatment procedures to manage telephone calls directed to a mobile phone via radio, which allow improving the service, eliminating the inconveniences due to communication barriers caused by the problem of a "mobile phone Inaccessible".

[0010] A further object of the present invention is to increase the number of free basic services offered to users by the network operator.

[0011] A final object of the present invention is to provide a procedure for the treatment of calls to an inaccessible radio mobile phone, and for the treatment of acquired related information, using the procedure protocols, technologies and standard components in the field of cellular mobile phones via radio , in order to allow easy maintenance and reduce the cost of implementing the procedure.

Description of the Invention

[0012] The scope of the invention is defined by the appended claims. These and other objects that will be evident from the description, are obtained through a procedure for handling telephone calls directed to a mobile phone via an inaccessible radio and for processing the information associated with the calling subscriber (such as the telephone number). , the time of the phone call and any additional information), in which the procedure is initiated (triggered) by an event such as a voice call, which in turn causes a notification through a recordable SMS text channel and includes the two different basic stages of:

I) route the phone call to a device for storing and managing data (information) related to the phone call, when the called subscriber is not accessible, because the subscriber's mobile phone is in disconnected mode or due to absence of a radio frequency signal, and when, at the same time, the call forwarding service to the answering service or another telephone number is not operational;

II) transmit, that is to say, notify the called subscriber, at the moment in which the mobile phone is accessible again, all SMS texts, including the data related to missed calls in the period in which the subscriber was not accessible;

The procedure is based on a protocol, in which the sequence of usual steps for making a mobile telephone network call is first started and then immediately interrupted after the signaling and acquisition of the subscriber identification, and this sequence of Stages resumes at the time it has been determined that the cellular mobile phone via radio is accessible again, but this time by activating an SMS text channel, to completely eliminate the sequence of real serial operational steps (transaction) typical of a protocol voice communication, thus producing, in fact, traffic that is virtual in nature.

[0013] The procedure described in this document is basically different from the known telephone calls diversion to the answering service, which in any case implies a complete operational sequence of stages of calls and serial responses (transaction) and, therefore, a cost to the user, which depends on the period of time during which the channel is busy. The service has been performed using TACS, GSM or GPRS technology, and could also be performed using UMTS technology.

[0014] Regarding the user, this service works according to the following stages:

- If a user is called while not accessible (cellular mobile phone in disconnected mode or absence of radio frequency signal), the calling user receives a voice message informing him that the called user cannot be accessed (this service is automatic , without any type of control option being performed by the calling user).

- Immediately after the called user is accessible again, he receives an SMS notification, which includes an indication of all phone calls missed during the period when he was not accessible. Notification is sent via SMS text to owners of a mobile phone via GSM radio and to owners of mobile phones via TACS radio adapted to receive and transmit SMS text messages, while notification is sent in the form of voice SMS in the case of TACS users whose cellular mobile phone via radio is not adapted to handle SMS text. The calling subscriber's phone number, the time of the phone call and any other relevant information regarding the calling subscriber and / or the called subscriber are transmitted at the same time. In case a user (with the same phone number) has called multiple times, only an indication will be provided regarding the most recent phone call. Also, if the number of missed phone calls exceeds the space available in a single SMS, additional SMS will be sent. Information regarding missed phone calls can be stored only for a maximum predetermined period of time.

[0015] The service is not activated in the following circumstances:

- The call forwarding service is already active, to an answering system or to a different phone number;

- The calling user's phone number is not available or is not presented (for example, a phone call from abroad, or in case of a hidden number, etc.)

- The called user is roaming abroad.

Brief description of the drawings

[0016] The preferred embodiments of the invention are described below for illustrative purposes only, without limiting the generality and possible applications thereof, said embodiments being shown in the attached figures, in which:

FIG. 1 is a schematic view of a network architecture, providing an indication of the operating procedure of the present invention;

FIG. 2 is a block diagram of a fundamental procedure within the scope of the method according to the present invention;

FIG. 3 is a block diagram illustrating a further essential procedure relating to the method of the present invention.

Best ways of carrying out the invention

[0017] It is now useful, before beginning the detailed description, to preliminarily present a list of symbologies and abbreviations actually in use in the technical field to which the invention relates.

1. DISCONNECTED: the user has turned off their mobile cell phone via radio by pressing the "OFF" key.

2. HLR Own position register: Database containing data related to registered cell phones.

3. IMSI: mobile identity via radio of the SIM card.

4. IP: network address defined in the Internet protocol.

5. IAM Initial Address Message: Signaling message containing information regarding the calling / called person.

6. ISUP ISDN User Part: GSM Network Signaling:

7. MAP Mobile application part: denotes (when MAP GSM is involved) the protocol used by the nodes of the GSM network to manage the mobility of users.

8. MSC mobile switching center: switching center for mobile telephony

9. MSISDN Mobile Station Integrated Services Digital Network: denotes the mobile phone number (eg 0338451845)

10. RADIO SEARCH: a radio signal broadcast from the MSC / VLR to inform the mobile phone via radio that a call has arrived.

11. PLMN: Public Land Mobile Network

12. PSTN: Public Switched Telephone Network

13. ITINERANCE: indicates a condition in which a GSM mobile phone happens to be connected to a network that differs from the network that issued the mobile phone's GSM card.

14. SMS-C: service center for short messages

15. STP Signaling transfer protocol: denotes a function of the signaling telephone network, which allows a signaling message to be transferred to its destination, passing through intermediate nodes.

16. TGDS TACS / GSM Gateway delivery system: Multifunctional hardware and software platform, implemented for the integration of operating procedures for wireless message systems.

17. UCP Universal Computer Protocol: Protocol used in the transmission of data to the SMS-C service center

18. VLR Register of visitor positions: database containing information regarding the actual position of the mobile phone.

[0018] With reference to fig. 1, this figure schematically shows the architecture used to provide this service, with the dotted lines indicating the functions of standard protocol stacks; on the other hand, figs. 2 and 3 denote the respective operating procedure used to carry out this service, which includes the following stages:

I) the calling subscriber 1 ', 1 "dials (step 30) the destination or" target "number and makes its telephone call interconnecting to a PSTN 4 telephone network, in the event that the telephone call is made from a fixed line 1 ', or to the PLMN 5 telephone network, in case the call is made from a mobile phone 1 ",

II) the original switching center MSC 2 interrogates the subscriber register 3 (hereinafter HLR), at 31, via STP 10, asking for the roaming destination number,

III) HLR 3 checks at 32 (based on the VLR number), whether the mobile phone is roaming abroad (this step is valid only for the GSM network).

- if the answer is "YES", the phone call is treated according to the usual procedure 33 foreseen in GSM networks, - if the answer is "NO", the procedure continues through the steps described below, IV) e1HLR 3 Check if the destination mobile phone is in the OFFLINE mode (34):

IV i) if the answer is “NO”, it transmits (35) to the original switching center MSC 2, the roaming number of the MSC / VLR center in which the destination number (destination center) is registered and the procedure continues as described below in steps V and later, which refer to checking whether the mobile phone is accessible;

IV ii) if the answer is "YES", it is checked - at 36 - if the destination number has enabled the call forwarding service to its own answering service or to another telephone number:

- if the answer is "YES", the number to which the call diversion is active is returned (at 37) to the original exchange 2 (MSC), and the procedure continues to return to step II;

- if the answer is "NO", the number of device 9 for storing and managing telephone calls (hereinafter also called "paging management") is returned (at 38) to the original exchange (MSC) 2 , and then the procedure continues as described in step VI.

V In case the preliminary check in the mobile phone's DISCONNECTED mode has led to a negative result, the destination center performs an additional test 40 in order to establish whether the destination (“target”) mobile phone is accessible:

- if the answer is "YES", the usual procedure for a telephone call starts at 33, following the common procedure established in mobile radio systems.

- if, on the other hand, the mobile phone is not accessible, a connection is established at 38, to the number of the device 9 for the management of paging, and the procedure continues according to the next step.

VI) If the mobile phone is switched off or is not accessible, and call forwarding is not enabled, the calling user receives an announcement and the phone call is routed to device 9 for paging management.

[0019] In order to increase the degree of reliability, the design is carried out in such a way that two paging management nodes are used. Both nodes share the same Database 14 of the phone calls, which is duplicated at the respective locations. In order to manage the correct synchronization and management of the two database systems, and in order to avoid access conflicts in the same records (as would happen when two users call the same person whose mobile phone is at the same time turned off or not accessible by a radio frequency signal), it was decided to define two different numbering series in e1HLR 3 for the forwarding of calls to the paging management device (these series are called “MSISDN Paging_1 Call Forwarding Number” and “ Call forwarding number MSISDN Paging_2 ”). The total number of numbering will be 10 (in order to leave a margin for possible future introductions from other paging management platforms), and they are formed by adding at the end of the numbering “47000” the last number of the called user's MSISDN Regarding who activates the service.

[0020] For this purpose, the paging management device 9, - that is, the device for storing and managing information regarding telephone calls to an inaccessible mobile phone -, satisfies a plurality of specific functional requirements that relate to the ability to cooperate, through the management of the ISUP protocol, with the switching nodes of the GSM network, and to the ability to extract the calling number from the ISUP IAM message for telephone calls directed to an inaccessible mobile phone or in case of absence of a radio frequency signal; Furthermore, the possibility is provided of storing in a dedicated Database 14 all the information related to the telephone calls directed to each mobile phone not accessible due to the absence of a radio frequency signal.

[0021] Furthermore, the paging management device 9 is suitable to cooperate with e1HLR, by managing the MAP protocol, for a switching request regarding the return of momentarily inaccessible mobile phones, within the area accessible by radio frequency signals. Lastly, it is also able to interact, - through the management of the UCP protocol -, with the SMS service center 11 of the GSM switching center, in order to send text messages to mobile phones that have returned within the area where radio frequency signals are active.

[0022] On the other hand, under the aspect of the procedural implementation of specific functions according to the present invention, the paging management device 9 successively performs the following operations: I - It receives, at 50, only the call signaling component Telephone, extracts the calling subscriber number from the IAM message from the ISUP signaling, records the time / date of the telephone call (within one second), and then issues an appropriate delivery message (at 51) regarding the MSC / VRL that is sending the data. This allows the MSC / VLR to possibly send a courtesy message (at 52), to the calling user, to deliver the phone call to release the voice channel;

II- activates a check at 53, in order to determine if the calling number is already in the list of numbers that have already tried to access this particular subscriber; Depending on the result of this check, it performs the following operations:

- whenever this number is already in the list of calling numbers for that subscriber, replace (at 54) the time / date of the last telephone call made by this user number, with the time / date recorded during the previous stage;

- if, on the other hand, this number is not in the list of calling numbers for that subscriber, add this number to the list (at 55), along with a time / date indication of the last phone call;

III - if from a test 56, it follows that the telephone call corresponds to a first telephone call, addressed to the called subscriber during the period in which it was not accessible, a request is made (at 57) to 1HLR 3 (through MAP ESTABLISHING DATA ^and s ^p ERA oF MESSAGE) to receive a notification immediately after the "target user", ie, the subscriber again be accessible.

[0023] When the recipient of the phone call is reachable again, e1HLR 3 communicates this fact to the paging management device 9. According to a preferred embodiment of the present invention, once the notification has been received, the paging management device paging subdivides the list of numbers associated with the target mobile phone into groups of four elements each, and for each of these groups defines a text message to be sent to the user, containing information related to the telephone calls included in this group.

[0024] The paging management device sends to the short message service center, 11, the messages defined above, through the UCP protocol, indicating as recipient the number of the destination mobile phone (that is, target).

[0025] Finally, the SMS-C sends the messages to the destination mobile phone when it is accessible again.

[0026] The system that performs the network architecture according to the previous description is suitable to provide a very high capacity of traffic management: it is capable of handling 350 telephone calls per second and up to 10 million telephone calls per day.

[0027] These performances are obtained through a logical subdivision of the network load in a plurality of nodes and through the use of technologies, which in part are already known and are already used in the field of telephony, but which they are combined through the necessary implementations, extensions and modifications, in order to finally provide users with a new free service.

[0028] This service is already enabled (by default), although the user can request its deactivation by calling and dialing a new special option from a voice menu; later, you can also request the reactivation of this service, taking similar actions.

Claims (4)

1. A method for the treatment of telephone calls in a mobile network comprising mobile switching nodes (2) and for the treatment of data relating to said telephone calls, wherein, for a telephone call from a calling subscriber (1 '; 1 ") to a mobile phone of a called subscriber, the procedure comprises the steps of: I- establish a connection with a device (9) for storage and management of data related to the phone call, when the called subscriber is not accessible, because the mobile phone is in the disconnected mode or due to the absence of a signal radio frequency, and when, at the same time, a call forwarding service to an answering service or other telephone number is not operational; said storage and management device (9) cooperating with the mobile switching nodes (2) by managing a signaling protocol; II- in said storage and management device (9), receive only the signaling component of the telephone call and extract the telephone number of the calling subscriber from the signaling component received of the telephone call, and register the telephone number and the time / date of the phone call in a list of numbers comprising the phone numbers of the calling subscribers who have already tried to access the called party's mobile phone; IIIa- in said storage and management device (9), cooperate through a protocol with its own Location Register (3) to receive from said Own Location Register (3) a notification when the mobile phone of the called subscriber is accessible again; Y IIIb- at the moment when the mobile phone of the called subscriber is accessible again, send from said storage and management device (9) to a service center for short messages (11) messages that include data, related to telephone calls, that they are included in said list of numbers; IV- send SMS messages that include said data from the short message service center (11) to the called subscriber's mobile phone. 2. A method for treating a telephone call according to claim 1, wherein stage II further comprises: a) checking, in said storage and management device (9), if the calling subscriber's telephone number is already included in said list of numbers together with the time / date of a previous telephone call; b) if so, replace, in the list of numbers, the time / date of the previous telephone call made by said calling subscriber, by the time / date of the current telephone call; c) if not, add the calling party's phone number and the time / date of the current phone call to that list of numbers. 3. A method for treating a telephone call according to any of claims 1 or 2, characterized in that step IIIb further comprises: a) grouping the information contained in said list of numbers into groups, each group comprising information about registered telephone calls, and b) for each one of said groups, define a message that must be sent to the called subscriber, which contains information regarding the telephone calls included in the group. 4. Mobile network comprising an HLR (3), an SMS center (11), mobile switching nodes (2) and a device (9) for the storage and management of data related to a telephone call directed from a subscriber caller (1 '; 1 ") to a called mobile phone when the latter is in disconnected mode, or when a radio frequency signal cannot access said mobile phone, and when, at the same time, a call forwarding service to an answering service or other telephone number is not operational, the storage and management device (9) comprising: - means capable of cooperating, through the management of a signaling protocol, with the mobile switching nodes (2) of the mobile network, to receive from them only the signaling component of the telephone call and extract the telephone number of the subscriber caller (1 '; 1 ") of said signaling component of the telephone call; - means for storing and processing data related to the extracted telephone number with the time / date of the telephone call; - means capable of cooperating with the HLR (3), by managing a suitable protocol, to make a request for a notification when the called mobile phone is reachable again; - means capable of cooperating with the SMS center (11) of the mobile network, by managing an appropriate protocol, in order to send an SMS message to said called mobile phone that has returned within the area accessible by radio frequency signals , said SMS message containing data regarding the extracted telephone number and the time / date of the telephone call.